How is this possible? The plugins used are the same trusted ones I use on all sites, and the other sub domains have been un-affected. And my user and password are pretty solid so I don't think the dashboard has been breached. It's not hosting side.

It took me a while to do my post below as i had several interruptions, and I see Paul posted the content that is found in the footer (hidden) but did not advise why. My post below deals with potential causes.

Your site has been hacked. More specifically, it appears that you have content that has been inserted into your database. The most common causes of this are a plugin or security issue in Wordpress. The content is being parsed into your footer.

But I think one of your plugins is the cause. They may be trusted, but one of them I think is the issue.

An autonomy of a plugin hack might be

1) plugin is mechanism to access the database2) the plugin could be a widget or shortcode that shows a block of text but if designed bad and allows a bad person to gain access to the databse they can run any query3) code is placed into the footer

The hacks are usually simple, something like: UPDATE wp_posts SET content = CONCAT(content,' ','Malicious HTML here') to append to all posts or pages.

Note that 99.9% of all web site hacks and infections are done by automated scripts and software. Someone did not go to your site, but rather an existing vulnerability was exploited by an automated script.

I would contact your host. Have your site restored from a backup. Then check all pages again. Also check to see if there is any reports of other users of the plugins experiencing the same thing.

I see you have 13 different plugins active.

Be advised that the route of going through your host may not work very well depending on when the database was infected. The absolute best way to ensure this does not happen is to export your striking settings, export all your content (this will not export your plugin content), grab your settings from your wp config file, and build a new database.

Its never fun when this happens. I should note that any plugin to do with social sharing, commenting, forms and embeds are typically the vehicles for such hacks.